Fatty acids are one of the principal components of lipids. In vivo, fatty acids are attached to glycerin via an ester bond to form lipids such as triacylglycerol. Many animals and plants store and utilize fatty acids as an energy source and these fatty acids and lipids are widely utilized for food or industrial use, for example, intermediate materials of foods, such as monoacylglycerol and diacylglycerol, and additives or intermediate materials for various industrial products. Further, higher alcohol derivatives that are obtained by reducing higher fatty acids having approximately 12 to 18 carbon atoms are used as surfactants. For example, alkyl sulfuric acid ester salts and alkylbenzenesulfonic acid salts are utilized as anionic surfactants, and polyoxyalkylene alkyl ethers and alkyl polyglycosides are utilized as nonionic surfactants, and these surfactants are used for detergents or disinfectants. Likewise, as other higher alcohol derivatives, alkylamine salts and mono- or dialkyl quaternary amine salts are commonly used for fiber treatment agents, hair conditioning agents or disinfectants, and benzalkonium type quaternary ammonium salts are commonly used for disinfectants or antiseptics. Furthermore, higher alcohols having approximately 18 carbon atoms are also useful as growth promoting agents for plants.
Fatty acids are widely used for various applications shown above, and therefore, it has been attempted to enhance the productivity of fatty acids or lipids in vivo by using animals and plants. For example, methods of increasing the lipid content in seeds by introducing acetyl-CoA carboxylase (ACCase) (Patent Literature 1, Non-Patent Literature 1, and Patent Literature 5); methods of increasing the lipid content in seeds by introducing a yeast sn-2 acyltransferase (SLC1-1) (Patent Literature 2, Patent Literature 3 and Non-Patent Literature 2); and methods of increasing the lipid content in seeds by introducing diacylglycerol acyltransferase gene (DGAT) (Patent Literature 4 and Non-Patent Literature 3), have been proposed. Further, several enzymes participating in the fatty acid biosynthesis are known, for example, a Elaeis quineensis-derived Acyl-ACP thioesterase (Patent Literature 6), a Cocos nucifera L.-derived Acyl-ACP thioesterase (Patent Literature 7), and a thioesterase having an amino acid sequence which is partially changed from that of an Acyl-ACP thioesterase derived from Umbellularia californica (Patent Literature 8).